1. Field of the Invention
This invention is in the field of thermally powered engines. This invention relates more specifically to thermally powered engines capable of utilizing relatively small temperature differences at relatively low temperatures to convert thermal energy into useful work. This invention relates more specifically to thermally powered heat transfer systems capable of effecting useful heating, useful cooling and useful mechanical work simultaneously. To accomplish these multiple purposes this invention incorporates a new and unique thermally powered engine to compress air. This new and unique engine may, in other circumstances, be operated to pump liquids. As incorporated in this invention this thermally powered engine can compress air. The heat of compression of the compressed air is a source of heat, the mechanical work potential of the compressed air is utilized to accomplish useful mechanical work, in this case to drive an electric power generator, and the cooling effect of the expanding air is used to operate a freezer and refrigerator.
This invention is specifically a significant improvement upon U.S. Pat. No. 4,418,547, THERMALLY POWERED HEAT TRANSFER SYSTEMS, issued to the inventor of this invention on Dec. 6, 1983. This significant improvement results from a new method for employing a liquid piston as described and claimed in U.S. Pat. No. 4,418,547. This new method, in combination with multiple pistons, separates total force exerted by a working fluid into two components: (1) the force necessary to return two pistons to their original position; and (2) the remaining net force which can be exerted by the working surface of one of the other pistons to accomplish useful work, such action taking place alternately. This separation of forces allows variation in displacement volumes, and this variation in displacement volumes is a significant improvement over U.S. Pat. No. 4,418,547. This improvement in turn extends the capabilities of this invention beyond those of the Thermally Powered Heat Transfer Systems of U.S. Pat. No. 4,418,547 and permits this invention to make useful all phases of the compression cycle sequentially.
This invention also incorporates a new method of sequential displacement, isothermal (and/or adiabatic) sequential displacement, this new method providing greater thermal efficiency at lower cost than the method of sequential displacement described in U.S. Pat. No. 4,537,037 entitled THERMALLY POWERED HEAT TRANSFER SYSTEMS UTILIZING SEQUENTIAL DISPLACEMENT, of which the inventor of this invention is the inventor, Isothermal sequential displacement can be used in conjunction with the earlier method. But this invention, utilizing isothermal sequential displacement, is capable of utilizing effectively the entire range of any given temperature difference, large as well as small, and thus can stand alone to achieve its multiple purposes.
2. Description of the Prior Art
The thermally powered heat transfer systems described in U.S. Pat. No. 4,418,547 issued Dec. 6, 1983 employs a two chambered compressor which acts with positive compressive action in both of the two possible compressive action directions; employs two heat sources to effect these compressive actions, one of these heat sources being located within the structure to be cooled when the system is used for cooling, employs two closed loops containing two different refrigerants, and employ two condensers both of which reject heat to an external heat sink when the system is used for cooling, the external heat sink having a temperature below that of the high temperature heat source and above that of the low temperature heat source. The thermally powered heat transfer system described in U.S. Pat. No. 4,418,547 permits the higher temperature heat source to have a relatively low temperature in comparison to the temperature required for the operation of other thermally powered refrigeration systems to accomplish the cooling of a structure.
The thermally powered heat transfer systems described in U.S. Pat. No. 4,530,037, employ sequential displacement and a larger temperature difference to improve the thermal efficiency of the thermally powered heat transfer systems described in U.S. Pat. No. 4,418,547. Sequential displacement is the general method whereby the same heat at sequentially lower temperatures can be used repetitively to accomplish the efficient heating or cooling of a structure or multiple structures.